NWS Area Forecast Discussion

000
FXUS61 KLWX 251832
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
232 PM EDT Tue Jul 25 2017

.SYNOPSIS...High pressure will build into the Mid Atlantic
tonight before moving offshore Wednesday. A cold front will
approach the area Thursday before passing through Friday into
Friday night. High pressure is expected to return for the
weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...Bkn-ovc low clouds over the
northern half of the fcst area early this evening. As high pres
builds to the north, winds will take a more easterly component
with a marine layer potentially developing along the western
shore of the Chesapeake Bay late tonight. A few showers or
sprinkles may develop along the shore. Patchy dense fog may also
develop over the valleys west of the Blue Ridge mtns.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...

Low Fog/stratus will mix out during the late morning or early
afternoon Wed. No wx is expected in the afternoon as subsidence
inversion will remain quite strong. A warm front will lift
through the area Thu with warm humid air moving in. Scattered
showers/t-storms expected in the afternoon mainly in the west,
then widespread showers/t-storms Thu night into at least the
first half of Fri as wave of low pressure moves across. Still
uncertainty in timing of frontal wave moving across and
instability available given expected widespread clouds and
showers. Both a severe and flash flooding risk are present with
flash flooding having higher odds at this time given potential
for repeated activity.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...

A closed upper level low is forecast to swing across the Mid-
Atlantic region Saturday. Low pressure along a cold front will
likely be moving south of the Mid-Atlantic region. Showers may
linger into Saturday until the upper level trough axis swings
through by Saturday evening. High pressure will move into the region
behind the departing sfc low Saturday night. High pressure will
likely be in control into the start of the work week.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...Bkn cigs 040 into early
evening. A period of clear skies expected this evening with
stratus expected to develop at BWI and MTN. Patchy light fog
also possible at CHO and MRB. Showers and t-storms likely Thu
night and Fri with flying restrictions likely at some point.

Improving weather Saturday night into Sun.

&&

.MARINE...Winds will continue to diminish through Wed night and
begin to strengthen Thu afternoon into Sat. SCA conditions are
possible during this time. SMWs may also be required due to
potential for convection.

Small craft conditions possible Saturday into Sunday, but winds
should be on the downward trend by Sat night.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$
SYNOPSIS...LFR
NEAR TERM...LFR
SHORT TERM...MM/LFR
LONG TERM...BJL/HSK
AVIATION...MM/HSK/LFR
MARINE...HSK/LFR

NWS LWX Office Area Forecast Discussion